Chemistry 103
50-Minute Class Examination #1
Monday, October 2, 2006
NAME:
NAME:
Score:
BLUGOLD:
Answer part A of each question if the digit of your BLUGOLD in the heavy box is 0, 2, 4, 6 or 8.
Answer part B of each question if the digit of your BLUGOLD in the heavy box is 1, 3, 5, 7 or 9.
The time limit for this examination is 50 minutes, not 51 minutes. I will apply time penalties to
exams turned in late. You may use a calculator for this examination. It is worth showing your
work: for questions requiring calculations, partial credit may be given for setting up the problem.
Useful constants:
Avogadro's number: 6.022×1023 mol–1
Planck's constant: 6.626×10–34 J•s
Rydberg constant: 1.097×107 m–1
velocity of light in a vacuum: 2.998×108 m s–1
1. (A) Fill in the blanks in the table for neutral atoms [14 pts]
Symbol
58
Ni
33
S
Number of
protons
Number of
neutrons
Number of
electrons
10
10
30
25
name of element
1. (B) Fill in the blanks in the table for neutral atoms [14 pts]
Symbol
Number of
protons
Number of
neutrons
Number of
electrons
name of element
65
Cu
86
Kr
78
117
46
35
2. (A) How many moles are there in 127.08 g of copper? [5 pts]
2. (B) How many moles are there in 6.75 g of aluminum? [5 pts]
3. (A) Magnesium has three stable isotopes, 24Mg, 25Mg and 26Mg. One isotope is more
abundant than the other two, which are present in approximately equal amounts.
Knowing that the atomic weight of magnesium is 24.31, which isotope predominates? [4
pts]
3. (B) Strontium has four stable isotopes. Strontium-84 has a very low natural abundance, but
86
Sr, 87Sr and 88Sr are all reasonably abundant. Knowing that the atomic weight of
strontium is 87.62, which of the more abundant isotopes predominates? [4 pts.]
4. (A) What is the mass of 1.23 moles of silicon? [5 pts]
4. (B) What is the mass of 2.34 moles of cobalt? [5 pts]
5. (A) What is the frequency of the most prominent line in the spectrum of mercury if its
wavelength is 253.652 nm? [5 pts]
5. (B) What is the frequency of the most prominent line in the spectrum of neon if its wavelength
is 865.438 nm? [5 pts]
6. (A) Calculate the wavelength and frequency of light emitted when an electron changes from
n=3 to n=1 in the H atom. [7 pts]
6. (B) Calculate the wavelength and frequency of light emitted when an electron changes from
n=4 to n=3 in the H atom. [7 pts]
7. (A) Complete the following table. If any combination is not valid, write "0." [12 pts]
Quantum numbers
Maximum number of orbitals with these
quantum numbers
n = 3, l = 0, m = +1
l
n = 5, l = 1
n = 7, l = 4
n = 4, l = 2, m = –2
l
7. (B) Complete the following table. If any combination is not valid, write "0." [12 pts]
Quantum numbers
n = 4, l = 3
n=5
n = 2, l = 2
n = 3, l = 1, m = –1
l
Maximum number of orbitals with these
quantum numbers
8. (A) Write a complete set of quantum numbers (n, l, m ) for one orbital from each of the
following subshells. [6 pts]
l
2p
3d
4f
8. (B) Write a complete set of quantum numbers (n, l, m ) for one orbital from each of the
following subshells. [6 pts]
l
5f
4d
2s
9. (A) and 9. (B) Identify each of the following orbitals [9 pts]
10. (A) depict the electron configuration of arsenic, As, using the spdf and noble gas core
notations. [8 pts]
spdf notation
noble gas core
notation
10. (B) depict the electron configuration of selenium, Se, using the spdf and noble gas core
notations.
spdf notation
noble gas core
notation
11. (A) Draw the orbital box diagram for the electron configuration of the magnesium ion, Mg2+.
You may represent the core electrons by the appropriate noble gas symbol. [5 pts]
11. (B) Draw the orbital box diagram for the electron configuration of the oxide ion, O2–. You
may represent the core electrons by the appropriate noble gas symbol. [5 pts]
12. (A) Arrange the elements As, Bi, N, P and Sb in increasing order of their first ionization
energy (lowest ionization energy first). [10 pts]
12. (B) Arrange the elements C, Ge, Pb, Si and Sn in increasing order of their first ionization
energy (lowest ionization energy first). [10 pts]
13. (A) and 13. (B) Arrange the halogen elements in decreasing order of reactivity (most reactive
first). [5 pts]
14. (A) and 14. (B) From the laboratory – On the atomic level, what gives rise to pressure in a
gas. You must be explicit to get these points. [5 pts]